Форум Радиолюбителей КВ - УКВ

Hello! This is my first post on this forum in English
As you can understand here will be discusiion, FAQ, etc about EU2AV Anvelina SDR transceiver. If you want to follow history of this SDR TRX, check this thread: https://eu2av.ru/viewtopic.php?f=4&t=141 and use Google translate but time by time I will publish news here as well.
Anvelina SDR are developed by Yuri EU2AV and he got very good parameters. Time by time there are folk who show interest to buy bare board of SDR, like ANAN 6000, 7000 or Orion for example. But real offers are rare and Apache Labs looks like do not plan produce bare boards anymore. There are not a lot of documentation about this project. Mainly it is distributed inside Russian speaking community. At this stage, this project needs to be advertised on English speaking comunity Author has extra PCBs. There are two of them. Main SDR PCB consist two ADC, thats mean DIVERSITY!!! There can be used mainstream LTC2208. But with LTC2217 it will goes around 6th-8th place in Sherwood list!!! There are some rumors, that after newest modifications it will goes to even higher place One ham made deep tests on this SDR board. It is named Anvelina Pro III, newest version. Even most biggest problem right now, are lack of ICs and other parts on market :-/ But possible source for parts are Aliexpress At least for BGA. It was possible to get it there for reasonable price, but now prices skyrocketing. And a lot of fakes :-/ Actually BGA soldering are worst part of this project. But as from feedback, on newest versions of boards with gold immersion, it goes much easier. Just these boards are more expensive.
You can check his Youtube channel: https://www.youtube.com/@eu2av/videos
Author show method, how to solder BGA. If follow all directions, even newbie can do it by himself
As well as, you can check neighbor thread: https://eu2av.ru/viewtopic.php?f=4&t=141
You can find HiRes pics of boards there. Not a problem to use Google translate. For skilled ham there shouldn’t be problems to build it up without help from side. But not all are like such a skilled.
I will try to help about this project, so much, how I can

Please pay attention!!!
I just realize, Youtube input spoken text into subtitles quite well As well it translate to English quite good Find button CC, it start to capture spoken text to subtitles. After go to next button Settings, push it and you will see Subtitles/CC, push it and there will be Auto translate, push it and there will be drop down list with languages, choose your But I wouldn't except good translation to languages other than English, German, etc. But who knows

Hello! For information, as you can see on right side, you can switch the language. There are not only English If you want more, let me know. Rules here are simple, as on most of the forums! Registration should be approved by owner Yuri EU2AV. Please remember exact time of registration, because of bots Yuri promise solve it in coming days. And let me know. At start you can do that through OpenHPSDR list, if you face up any problems. Or you can sort out from there what is my email I will try to start fill it up with information

I am very curious about your reports on construction and component procurement. As already said, I would like to get involved in this project, but the current problems with the components let me refrain from doing so for the time being. But of course I will read along here as well.

Right now there are problems, but it is possible to get over them Mostly there are skyrocketed prices on some parts BGA and KSZ9031 are most problematic part. It is possible to get on Ali, but big chance of fake As well for example LTC2217 in reality are LTC2208.

Anvelina SDR deep testing by RX3AM Later he will publish test results.

A small comparison in terms of current consumption, on the first board there is a good thermostatic generator with it, the total consumption came out to 970ma, in the second case it is a conventional generator 7N-10,000MBP-T =680ma
https://www.youtube.com/watch?v=ebxqe1XviDg

Neighbor transmits on ICOM-910, 100W, 1km away By the way, it is with new Yuri EU2AV 144Mhz transverter
https://youtu.be/2QAEOs_q9SM

Some images

https://youtu.be/qakGzktRxEw

One more demonstration Later I will translate it

Here is another photo of the amplifier board, a current sensor and voltage measurements were added in the latest revisions. There is also a jumper on the board, when it is activated, the reverse mode turns on- that is, when we work on the VHF channel of the receiver RX2 is connected to the input RX1, so in VHF mode with the second receiver I can listen to 160-6m, which seemed very convenient to me. If the JP2 jumper is not soldered, everything will be by default (without reverse)

Got a new case ordered from Oleg EU1AV that's what how does it look's like
https://www.youtube.com/watch?v=LlYkePfVGbo&t=475s

Hi All,
i have successfully implemented Avelina SDR III with its 100W Amplifier.
73
Luca IK2LRN
Italy

Luka Welcome This is good news for me Thank you
I wonder what kind of power turned out on the 6m range ?

Hi Yury,
at 6m maximum power is about 80w
I am currently start to build your new 3.6 version.
73
Luca

Hi Yury, in the new Amplifier version 3.6 there are some capacitors and resistors with the indication R* and C*. Please refer with the red circles in the attached picture. Please let me know what does it mean.
73
Luca

Luka Hi! I have about the same result on 6m, by selecting capacitors in the output transformer, you can bring the output power to 100 watts, but I think it is absolutely not necessary for 6m. This is the version of the board (3.6.0) practically does not differ from version 3.6.1, so it is better to use Bom 3.6.1 there the values of the capacitors in the LPF are well debugged. As for the C* capacitors, this can additionally be used for better matching, you can set values of 100p, in most cases you can not use (No/set). R* definitely does not need to be set, it was for an experiment.

You may have already paid attention to the new bom, for the PS-A function to work well, you had to change the values of the resistors R60, R61 by 10k. If the transistors are original RD100, then the resistors R47, R48 by 5.1K, but with such changes there is a problem with D51, you need to make a revision, after which the quiescent currents will be easier to set. If RD100 is a well-matched pair, then you can leave it as it is (D51).

Hi Yury,
thanks for the detailed information.
In order to avoid confusion i ask if you can please provide the updated schematics.
For the implementation i have used as reference
the values indicated in 3.6.0 schematics.
I have not used bom
73
Luca IK2LRN

Luka Hello! This is the right approach to use the scheme Below I attached an archive with diagrams and revision. The photo shows that in the gap of the legs 1,2 (D51) it is necessary to put resistors of 20k, for more accurate operation of the thermistor they can be more accurately selected.

Hi Yury,in order to update to 3.6.1 i have replaced 1) allmost all the LPF capacitors 2) R36 1.2K 3) R56-59 22ohm 4) R60-61 33K 5) add 2x22k at D51 (see picture).
If you remmember others variations please let me know.
Thanks, 73
Luca IK2LRN

Luke Good evening! In the new BOM 3.6.0, I managed to find the right values of the capacitors, I got good repeatability, I used these capacitors https://lcsc.com/product-detail/Multila ... 07177.html
As for the resistors R61, R62, an increase in the value only has a better effect on the operation of PS-A, I tried to reduce it to 10k and did not see much difference.

Luka, you did everything right, I did it differently, used a blade, made cuts of the tracks at the right points, I attach a photo below. Let me remind you that if the RD100 is well matched, this modification can be omitted, after the alteration I did not see absolutely no difference in work (PA). If do not do this revision, the only thing that is not convenient is setting the voltages at the gates of transistors.

Hi Yuri, which is the best companion antenna tuner solution for your 100W amplifier?
Do you have think about integrate ATU in your enclosure?
I have already ordered your new enclosure, It should arrive in soon.
I have an antenna wire dipole than antenna tuner is absolutely required.

73

Luca IK2LRN

Luka Good evening! On the BPF-PA board, just in case, such an option was provided, if you do not solder the corresponding jumper that is located on the back of the board, then we can connect any tuner to the connectors that are written Option ATU, so we connect it in front of the antenna switch, which is convenient. The simplest solution for today! I would recommend using a simple atu of the n7ddc design, also do not forget that any tuner makes a deterioration in the bypass mode on the hf bands (10-6m), therefore it is better to use the 5x5 version. It is not difficult for me to develop the tuner card itself, the whole problem is in writing software, the best option is to write a tuner program in Thetis itself, so it will be possible to organize memory for three antennas and the most convenient thing is that the ATU will be able to switch memory in reception mode, three or four pins from the SDR board are enough to control the tuner card, for example with J18. I myself know very superficially (C#), so it would be interesting to find someone who could join such an idea.

As for where to place the atu, if you do not plan to make a VHF converter, you can install a tuner in its place.

Hi Yuri, i am currntly building also your 2m Transverter. With reference to attached picture i didn't found the following informations, at schematics and BOM:

1) L21,L22,L23,L9,L12 : wire and coil diameters, coil lenght (turns spacing)
2) Front Side: C* capacitors
3) Rear Side c, cf1,cb1,cb2,cb3,cb4, CA1, CA2
4) Q3 bias [mA]
5)Q4 bias [mA]
6) How to set C48, C80
7) How to set RV2 (122 MHz input)

Thanks, 73
Luca IK2LRN

Luca Hello! What output transistor do you plan to use? Coils L21,22,23,9- can be made with a 0.9-1.0mm wire, the inner winding diameter is 3mm. Adjust L21,22 by expanding or compressing (at maximum power). The L12 coil is wound with a 0.5mm wire - the inner diameter is also 3mm. Solder capacitors only cf1, cf2 at 100n. Do not solder the rest. C48, C80 set to maximum power. RV2 need to set required RF voltage to ADE -12 (122.88-LO=0.9V)

Hello Yuri,
which is the best transistor for this Transverter ?
73
Luca

The best option is to use the RD70HUF2 transistor, with this I managed to get an output power of 55-58 watts, in SSB I advise you to shoot up to 40 watts of output power. With Transistor RD70VHF output power will be up to 35 watts.

I have just ordered RD70HUF2. Please let me know the bias required.
73 Thanks
Luca IK2LRN

Luca Hello! Excellent is a good choice. Now I am finishing the assembly of new VHF transverter boards, in the next two weeks I will open a new topic, show photos of aluminum linings for RD70HUF2, and linings for rd07..

Hello to fans of transceiver Anvelin pro 3. Today I want to talk about my build version of this wonderful transceiver. The beginning of this whole venture appeared in January 2022. And the end of the project, before the last screw is twisted, in September 2022. I learned from my colleagues of radio amateurs that in my city of Soligorsk, Belarus, this transceiver was designed and assembled by Yuri EU2AV. All documentation was available to him, as well as many reviews on YouTube and its website http ://ew2aavw3.beget.tech/. I was also allowed into the telegram chat to communicate on the issues of assembling and setting up the transceiver. I read a lot about transceivers with similar characteristics: the ANAN line, FlexRadio, Icom, Yeasu, sdr ddc duc transceivers of Russian developers, etc. Considering many factors: quality, feedback, appearance, form factor, signal visualization quality, intuitive interface, flexibility of control, openness of many settings without playing the tambourine, the ability to upgrade, versatility and constant software updates, price, the ability to assemble and customize with your own hands, used components, availability of 2 physical receivers with separate range filters by input, the presence of 2m range, 100 w output power, as well as the presence of Yuri EU2AV himself in the next house, which is always, if anything, at hand!!! Hi! As it turned out later I was very useful!!! I myself do not have a certified education in the field of radio electronics. Since childhood, I was attracted to the radio. I am an ordinary average amateur radio user with little skills in catching and repairing simple radios. By training, I'm a doctor. At the beginning of my journey to study and assemble Anvelina, I imagined this transceiver as drawn squares in a block diagram on paper and nothing more. The software for me was a dark forest. But the motivation is persistent and the process has gone...
I ordered 3 boards from Yuri when assembled: SDR transceiver, power amplifier with band filters, 144 MHz transverter. Also from a radio amateur from Minsk, Oleg EU1AV I ordered a new building (his own development), which was specially developed for this transceiver in collaboration with Yuri. Separate thanks to Oleg for such a high-quality building. The quality of fitting parts, the accuracy of drilling holes, design, painting, routing cables, engineering of air flows for cooling the entire structure - everything is fine. In the hands, the case looks like a complete design, visually, as if made at a factory in Europe or Japan. What can I say, milling aluminum with a thickness of 10 mm, painting in a furnace. All the necessary holes for connectors, just insert and screw. The accuracy of fitting the panels directly into the lapping is clear. Assembly with screws in sweat under a hexagon!!! There is no luft at all. I am very pleased!!! This building and Anvelina about 3 are directly created for each other!!! I only have to marry them! Hi!

I received many different cables, connectors, adapters in addition. The work boiled over.
I want to immediately warn you that the transceiver is going into the case and works perfectly without improvements, without finishing, but I, only for myself, decided to make some improvements in my opinion.
Given the modernization carried out by Yuri to reduce the current consumption of the transceiver, I still decided to make my aluminum gaskets for contact of voltage stabilizers with the radiator. It was made into a hand made of aluminum plates with a thickness of 5 mm with small files. Repeatedly adjusting the minimum clearances. I don't have a cutter. Photo.

He also turned the gasket under the transistors of the power amplifier. photo,

and made a new radiator gasket for the transverter. photo.

There were gaskets, but I wanted to increase the contact area of the heating parts with the main radiator. After this refinement, the rotation speed of the fans decreased, and the background noise from them at the reception decreased.

Then I wanted to see the scatters under the antennas of the SO239 sticking out from the inside. See photo. To do this, I had to cut off part of the power amplifier board in the contact area where the wires are soldered to the SO239. Photo.
The inside of the back wall of the case was cleaned of paint along the perimeter of contact with the connectors and screwed them in. It turned out beautifully. Without clipping the board, these dimensions are screwed on the outside.

He specifically paid attention to cable management. All signal wires passed through the copper sleeves. I took the braid from the RF cable. I tried to spread the wires around the perimeter of the case, and so that they did not interfere with the flow of air from the fans. He put ferrite rings on the wires. At the final stage, in order to prevent oxidation of copper, all cables were removed and retained in the form of bends converted as a result of laying, covered with a transparent autolak. The cables turned some stiffness, began to shine. After 2 hours, the varnish dried up and I put all the cables in my places. Everything became clear.

transverter montage radiator

only sdr

audio spiker montage

sdr+ transverter in box

amplifaer +kabelmanagment

Carried out 2 more improvements:
1) Added a variable resistor to the circuit to adjust the fan speed in reception mode. Reduced the speed, the noise of the fan decreased, and the air flow did not feel much changed. Taking into account the modernized gaskets for the radiator, about which I told the transceiver to the reception, it remains cold, not warm, but cold.
2) Improved the function of increasing the fan speed when operating for transmission in the range of 145 MHz. Previously, when transmitting at 145 MHz, fan speeds did not increase. As far as I know, Yuri will introduce these improvements into the board of the next version of the amplifier.
3) Photo of the completed transceiver.
He did everything slowly in the evenings, enjoying the process.

Excellent FAQ/HOW-TO

Hi Yuri,
i would like to know if it is foreseen an further evolution of the SDR Avelina.

Luca

HI, I WOULD LIKE TO KNOW WHERE I CAN PURCHASE GOOD QUALITY SPEAKERS THAT FITS WITH THE ENCLOSURE.
Visaton SL 87 ND - 8 Ohm is suitable for that purpose ?
THANKS, 73
LUCA IK2LRN
ITALIA

Hi Luca As situation on electronic parts market are highly volatile, it is hard to say when there will be next gen. As well as, you can see situation in China became quite volatile. But China are PCB boards and parts source.
As of speakers: https://www.aliexpress.com/item/32835651663.html
These are very good

Hi, thanks for your reply.
Visaton speakers has 40mm deep. There are some mechanical constraints in terms of deep ?
Luca IK2LRN

Hi Yuri,
i am begining to study the beautiful Avelina encloure before to start to install the boards.
I have some questions regarding it:
1) Spacers height for PCBs
2) How to install the Amplifier heatsink spacers that i have received with the enclosure. In particular regarding the smallest. Please refer with the picture
3) Drawings for design a proper heasink spacer for the transverter
4) Type of screened cable to be used for cabling.

Thanks

Luca

Luka Hi! The lining for the rd100 is made taking into account the fact that the bpf-pa board is installed on 5mm racks. Two small pads were designed for the VHF converter, apparently eu1av messed up when sending, but if you drill holes, it is quite possible to use it for the SDR board. For the SDR board, here is such a lining, I also use it for the VHF converter

Hi Yuri. thanks for your very useful informations !
I have a question relating the 12VDC power switch in enclosure front panel : how i can manage 10A using a small push button ?
Maybe a Latching relay ?
I have something missed in the Amp schematic ?

73

Luca IK2LRN

Luca Hello! No, not so The bpf-pa board always has power, the power to the sdr board is taken from the J19 connector, that is, only the sdr board is connected through the switch. Note that the bpf-pa board also has a power connector for powering a VHF transverter that uses an ACS713 current sensor.

OK Yuri,
In have experimented that Avelina take the power, from Amp,through Alex connector. It is normal ?
How to simply avoid it ?
Luca

Luka, no, not really. The power supply from the Alex connector must be done for fans, that is, when we turn on the SDR board with the power button, the fans start working. It is worth considering that the JP near the Alex connector should not be shorted, this jumper can be used purely for debugging.

Hi Yuri
for the fan do you suggest to use simple 2-3 wire fan or 4wire speed control PWM fan ?
https://www.aliexpress.com/i/4000603214374.html. I could measure heatsink temperature for drive the fan.
I don't know if pwm could generate interference.
I suppose that the 2 fan configuration will be push-pull.
73
Luca IK2LRN

Luka Hi glad to hear:) As can be seen from the PWM circuit is not used, a simple analog control is made here, I usually use fans with three pins, the third pin is not used in our case. In fact, at the very beginning there was an attempt to apply PWM control, as a result, it works very well, but with the antenna turned off, interference could be observed, for this reason we had to exclude this option.

Hi, attached the pictures of my work in progress.
I am currently studying the mechanical constraints.
73
Luca

Luka Hi! I see the process is actively moving forward :,)

Hi Yury, it is necessary to make a M3 threaded hole in the shelf for install the heasink for Transverter and Avelina small transistors ? Can you please show me how do you have intall it ?
Thanks,
73
Luca IK2LRN
Milano Italia

Luca Hello! You only need to drill and cut the thread for the transistor, I indicated the photo with an arrow. The remaining two pads are glued with thermal glue, before installing on the chassis of the transceiver, you need to apply a small layer of thermal paste

Hi Yury, thanks for your very useful answers.

I have a question related the digital input-output cabling.
If i have understood well :
1) rear RS232 connector OC OUTPUTS should be connected to J16 PIN 17-24
2) rear PTT-IN should be connected to J16 pin 1
3) rear PTT should be connected to J16 pin 25

4)Watching the pictures of your video i not understand wy same cables are connected to J18. Please refer with attanced picture.

5)I have also not undestrood yet the function and connection of the front panel REMOTE 3.5mm Jack

Thanks !, 73

Luca IK2LRN

Luca Hello! In the archive Bootloader_Bom_Anvelina - there are descriptions of J16, J18. XVTR TX-control is output to J18 pin-4, you need to connect this wire to J6 which is on the BPF-PA board, from the same J6 take control for switching the PTT of the VHF transverter. Below I have attached a photo of how I made my pinout from J16 to the DB-15 connector. Bootloader with J16 brought to jack 3.5 which is on the front ponel.

OK Yury, now I think that it is clear the flat cable connection.

Regarding the front panel i do not understand the function of the "REMOTE" 3.5mm plug.

Thanks, 73

Luca IK2LRN

Hi Luca It is J17 jumper, you won't open case each time when you need to short it Yuri doesn't feel good right now, he got severe flu or like that

Hi all

My name is Marc, slowly building an Anvelina board.

... and for this reason, I have some probably stupid questions.
First of all, two notes in the schematic are a big mistery for me (as written in cyrilic alphabet)

https://imgur.com/a/e6ugDud



could someone translate this subliminal message for me? I would be very grateful.

I also wish to know the role or function of R169 and R170. They probably have some relation with the FWD/REFL measurement, but I don't understand how.

Tnks in advance
73'
Marc f6itu

Oh, by the way Yuri

PCB release 3.5d and schematic release 3.6D, IC13 is NOT grounded.
... thus causing probable glitches in the Alexiares SPI protocol. Pin 19 and 1 ( OE1/OE2) could go high and stuck all communication with Alexiares address decoder

A short strap with the closes gnd plane is advisable

73'
Marc f6itu

I listed partly soldered Anvelina PROIII REV3.4E board on Ebay.
https://www.ebay.com/itm/334848874757
Later I will create thread about these version DIY specific. Where to get parts, etc.
As well as thread to offer other boards. Prices on forum will be more friendly, due to high fees on Ebay. For customers, who will buy these boards, there will be possibility to buy long/hard to get parts. For those who do not feel so skilled or had a lack of tools, BGA soldering service will be available.
DISCLAIMER!!!
As this is highly advanced DIY board, you should have certain knowledge, experience and tools!!! As of my experience, most of the problems at this board DIY process come from luck of previous mentioned things. All questions/answers about building only on forum!!! I hope so our community will be helpful to those who will dare to DIY this board
Feel free to ask

Hi Yuri,
i have completed the enclosure cabling except for the Transverter since i have not yet tested it.
You can see the results in the attached picture
I have found two minor problems:
1) Fan voltage remain fixed at 8,2V even if i turn the trimmer
2) When i turn on the radio for the first two seconds i hear a noise in the speaker.

73
Luca IK2LRN

Hi Yuri, i have a question related the FAN control.
When the Avelina start correctly the ultra low noise Notchua 12VDC FAN start with enough speed, with supplied voltage 9,9VDC , at J15.
The Value of the voltage at MJD122-1G Q7 , refer to ground, are the following:
collector 13,7V
base 7,86V
emitter 9,9 V in Rx . 9,6V in TX
I have not understand how it works and how 10K RV3 trimmer should be adjusted.
Like it is suggested in the 3.6.0 bom i have used the following resistor values:
R71 20K
R70 33K
I suppose that if the temperature increase the NTC reduce the resistance and the speed increase.
I have applied a 10Kohm resistor in parallel to NTC but the voltage at emitter do NOT increase.
Can you help me ?
Thanks, 73
Luca IK2LRN

Luca Hello! I apologize for the long answer, now in the summer I often travel. In older versions of PA boards, the potentiometer is only for TX (RV3), turn on the gear and set the desired speed. I should also say about the fans, I use (140-150mA) Zalman ZM-F1 PLUS (SF) 80 mm. To set the minimum speed for RX, you need to select the resistor R89. As for the thermistor, you need to put this type https://www.aliexpress.com/item/1005004 ... CPvEF&mp=1

IK2LRN писал(а): ↑05 июн 2023 22:18 Hi Yuri,
i have completed the enclosure cabling except for the Transverter since i have not yet tested it.
You can see the results in the attached picture
I have found two minor problems:
2) When i turn on the radio for the first two seconds i hear a noise in the speaker.

73
Luca IK2LRN

As for the noise in the speakers, I did not observe such a problem, I use this 8ohm speakers https://www.aliexpress.com/item/1005003 ... a396h8mSbZ

Hi Yuri

Could you please give us some news concerning the 2m transverter ?

I saw Luca's build and I must admit I'm very interested if this version is stable

VY 73'
Marc

Mark Hello! There is news, there has already been more than one revision, while I got what I wanted. The main drawback of the previous version is the output transistor (RD70HUF2), which turned out to be not reliable if you remove more than 50 watts from it. In the new version, today I have used the AFT05MP075N transistor, now when it is turned on for a long time in the FM at a power of 70-80 watts, there are no problems, also in the new version there is protection, if the SWR exceeds 1.4-1.5, the output power drops to 1-2 watts, very convenient if you forgot to connect the antenna to a friend Not many photos yet Scheme and bom:

Tnks Yuri

In other words, quite a lot of good news.

I'll ask Aivars if he can send me a pcb of the new release (if available)

I have a small amount of AFT05MP075N in my junkbox (who could ask for more ! ) But I'm affraid you'll have to make a new release in the next future, as NXP has announced the end of production of this device :- (( For the moment, Mouser and other distributors have still some stock, but I won't bet it will last long.

Anyhow, it's a really robust stuff. I'am using it in the short wave bands. You've probably seen Manfred's 50W amplifier for the Red Pitaya
https://ludens.cl/Electron/50Wamp/50Wamp.html

VY 73' Yuri

Marc f6itu

Mark Thanks for the info, it's really interesting, I didn't think that this transistor could work well per sq. This transistor is used in the icom-9700, they take 100 watts from it, I didn’t pump more than 80 watts. As for the imd-3, I got -32-30dB at a power of 50-60 watts. In the future, it will not be easy to find a worthy replacement, it will be necessary to see what is from a similar series.

Hy Yury,
regarding 2m trasnverter i have investigate about the problem on mixer M1.
Referring with rear of PCB in a previous post you told me that to apply only cf1 and cf2 with value 100nF.
The the points highlighted with an arrow are connected to ground than the input and output filter is connected towards the the ground with 100nF.
I think that this is not correct.
I not understand where this point are connected. It is no visible the printed circuit line.
Please let me know.
Thanks 73
Luca

Hi Yuri

I have a desperately empty and useless connector on my SDR back panel :-d
if you need a beta tester for your AFT05MP075N version of the transverter, count me in. Even a simple set of gerber files will be ok

Wish you all the best

Marc f6itu

Hi my SAW filter for 2M Transverter is defected. Cover 145-147 instead of 144-146. I ask if someone have one for sale or let me know when i can purchase it.
Regards
Luca IK2LRN

Hi Yuri & Luca

the passive bpf filter shows approximately 3.9 dB of insertion losses @ 144 MHz and 3.6 dB at 146 MHz with approximately 1,3 dB ripple and a usable 138/148 bandwidth (It could be better tuned, but is it really necessary to spend more time on it ? )


SAW filters are not exactly efficient for post-mixing section, as Luca said, a true 144/146 MHz SAW is quite impossible to find. We don't need a bandpass filter here, but an hamonic filter to cut f.OL +/- F.IF, in other words around 102and 168 MHz and mixing products up and down. The "passive" bpf shows a 25 to 30dB attenuation on these frequencies

May I suggest to use a couple of MCL SXBP-150+ filter in series ? Insertion losses won't go bellow 4 dB (2 dB at 140 and 160 MHz per filter), better impedance control, better group delay, far better Q and a rather low VSWR for a little bit narrower bandwidth. An no tune hassle

... and it could easy fit on the piggy-back pcb

what do you think about ? it will be far easier to source than elliptic filters (rota franco's successor has incredibly high shipping fees)

73'
Marc f6itu

Hi Yuri & Luca

the passive bpf filter shows approximately 3.9 dB of insertion losses @ 144 MHz and 3.6 dB at 146 MHz with approximately 1,3 dB ripple and a usable 138/148 bandwidth (It could be better tuned, but is it really necessary to spend more time on it ? )


SAW filters are not exactly efficient for post-mixing section, as Luca said, a true 144/146 MHz SAW is quite impossible to find. We don't need a bandpass filter here, but an hamonic filter to cut f.OL +/- F.IF, in other words around 102and 168 MHz and mixing products up and down. The "passive" bpf shows a 25 to 30dB attenuation on these frequencies

May I suggest to use a couple of MCL SXBP-150+ filter in series ? Insertion losses won't go bellow 4 dB (2 dB at 140 and 160 MHz per filter), better impedance control, better group delay, far better Q and a rather low VSWR for a little bit narrower bandwidth. An no tune hassle

... and it could easy fit on the piggy-back pcb

what do you think about ? it will be far easier to source than elliptic filters (rota franco's successor has incredibly high shipping fees)

73'
Marc f6itu

ps : quick and dirty measurement of the 2 coils filter, narrow and larger bw

Hello everyone

I'm very late, but I've finally found the time to complete a prototype for the 140-150 MHz filter of Yuri's transverter.

Advantages:
- Uses just two easy-to-find components (SXBP-150 from Mini Circuits Lab)
- No tuning, no vna measurements required
- Impedance centred on 50 Ohms at input and output
- Insertion losses at 4 dB maximum (2-filter cascade version) and 2 dB (1-filter version)
- Rejection at 100 and 180 MHz greater than 70 dB (50 dB for the mono-filter version)
- Quick assembly, in less than 10 minutes
- Respects the footprint of the original filter

Disadvantage:
- Price. The mono-filter version costs approximately 26 euros, and 32 euros for the dual version.

The following measurements were carried out using a LibreVNA 0-6 GHz analyser, with 1500 measurement points between 100 and 200 MHz, after calibration on a Calkit Anritsu.
The filter « on board »
https://github.com/F6ITU/Double145BPFfi ... uation.jpg

the amplitude of a single filter
https://github.com/F6ITU/Double145BPFfi ... %20S21.png

the amplitude with two cascaded filters
https://github.com/F6ITU/Double145BPFfi ... %20S21.png

the reflected Z at the input port for a single filter (solid 50 Ohms, thanks to MCL)
https://github.com/F6ITU/Double145BPFfi ... %20S11.png

the Kicad and Gerber files and the documentation are available on my github,
https://github.com/F6ITU/Double145BPFfilter/tree/main

and of course via Aivars

I'd like to thank Aivars who took an active part in this project and encouraged me not to drag things out too much.

... and of course, a big thank you to Yuri for the work done on his transverter.

73'
Marc f6itu

Thank you Marc